Brake drum with vent hole and cooling scoop

ABSTRACT

One embodiment of a brake drum includes a cylindrical main body portion, a brake drum mounting flange portion, a brake drum transition portion, the brake drum transition portion extending between the cylindrical main body portion and the mounting flange portion, the transition portion having a plurality of vent openings, and one air scoop secured at each of the vent openings, whereby rotation of the brake drum and air scoop induces air movement within a brake drum cavity defined by the main body portion. Each air scoop defines a louver opening which faces the angular direction of drum rotation, an air channel in fluid communication with the louver opening and the brake drum cavity, and a deflection surface located in the air channel. The deflection surface is positioned to re-direct air movement entering the louver opening at an angular direction, to a generally radial and inboard direction

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.60/754,010, filed Dec. 23, 2005.

TECHNICAL FIELD

The present invention relates to providing air flow to a vehicle brakedrum during operation of a vehicle such as a truck, bus and trailer,and, in particular, to enhancing the ventilation of a vehicle brake drumhaving vent holes.

BACKGROUND OF THE INVENTION

The prior art includes brake drums for vehicles, including medium andheavy-duty trucks, trailers and buses. In order to slow or stop a movingvehicle, the braking mechanism is activated to urge the brake shoes andbrake lining into engagement with the friction surface of the brakedrum. The frictional engagement of the brake lining with the brake drumcauses the vehicle to slow or stop. However, in the process, the kineticenergy of the moving vehicle is converted into heat. Further, thefrictional engagement causes wear on the brake lining which producesdebris in the form of brake dust. Over time, a substantial amount ofbrake dust may accumulate within the brake drum and surrounding area.The accumulation of brake dust impairs the performance of the brakesystem, such as reducing the effectiveness to dissipate heat, andcreating noise during operation of the brake system. Still further, roaddebris enters the brake drum and further impairs performance of thebrake drum.

The prior art includes various means for providing and enhancing coolingand ventilation to the brake drum, in order to remove the heat, debrisand lessen noise. For example, U.S. Pat. No. 3,127,959 is directed to acooling device for brake drums and shoes. The cooling device isinstalled within the brake drum. In particular, the cooling deviceincludes a disc, the body of which is provided with a plurality of vaneswhich form air circulating blades when the disc is rotated. The disc isplaced over the outer diameter of the wheel hub. The brake drum is theninstalled and receives the disc within a cavity formed by the brakedrum. A magnet secured to the disc draws and holds the disc axially ofthe drum by magnetic force on the hub flange. U.S. Pat. No. 4,989,697 isdirected to a cooling, cleaning and drying means for brake drums. Inparticular, a generally circular elongated flexible air scoop strip isprovided and includes mounting holes and outwardly protruding airscoops. The strip is mounted within the brake drum and secured in placevia bolts which extend through the mounting holes and through the brakedrum.

The prior art also includes cooling devices which are installed on anexterior surface of the brake drum. For example, U.S. Pat. No. 2,896,749discloses a brake drum cooling device having a plurality of ringsegments joined together at their ends by means of turnbuckles. Theturnbuckles serve to clamp the segments against the outer surface of theflange of a brake drum. U.S. Pat. No. 2,659,459 discloses a brakecooling ring which is secured to the outer surface of the brake drum viabolts which extend from the hub and through the brake drum.

It is also known to provide full cast transit brake drums with ventopenings.

While advancements have been made to address the foregoing and otherrelated problems, there still exists a need for further improvements.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a brake drum havingimproved ventilation.

It is a feature of the present invention to provide improved coolingfeatures.

It is a further feature of the present invention to provide a brake drumwith improved cleaning capability.

It is still a further feature of the present invention to provide abrake drum having features which reduce the tendency for certainoperational noise.

It is still a further feature of the invention to provide a device whichmay be retrofitted to brake drums to enhance the ventilation of thebrake drum.

It is still yet a further feature to provide a ventilation device whichmay be installed on a brake drum, regardless of whether the brake drumis to be installed on the left or right side of a vehicle.

The present invention therefore provides a brake drum having acylindrical main body portion, a brake drum mounting flange portion, abrake drum transition portion, the brake drum transition portionextending between the cylindrical main body portion and the mountingflange portion, the transition portion having at least one vent opening,and an air scoop secured at the vent opening, whereby rotation of thebrake drum and air scoop induces air movement within a brake drum cavitydefined by the main body portion.

The present invention also provides a brake drum comprising acylindrical main body portion, a brake drum mounting flange portion abrake drum transition portion, the brake drum transition portionextending between the cylindrical main body portion and the mountingflange portion, the transition portion having an outer surface and atleast one vent opening; and an air scoop secured at the vent opening,the air scoop includes a louver opening and extends outwardly from theouter surface of the brake drum transition portion, whereby rotation ofthe brake drum and air scoop induces air movement within a brake drumcavity defined by the main body portion.

The present invention further provides a brake drum comprising acylindrical main body portion defining a brake drum cavity, a brake drummounting flange portion, a brake drum transition portion, the brake drumtransition portion extending between the cylindrical main body portionand the mounting flange portion, the transition portion having an outersurface and a plurality of vent openings, and an air scoop secured ateach vent opening and which extends outwardly from the outer surface ofthe braked drum transition portion, each air scoop defines a louveropening which faces the angular direction of drum rotation, an airchannel in fluid communication with the louver opening and the brakedrum cavity, and a deflection surface located in the air channel, thedeflection surface positioned to re-direct air movement entering thelouver opening at an angular direction, to a generally radial andinboard direction, whereby rotation of the brake drum and air scoopinduces air movement within the brake drum cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a brake drum having vent holes inaccordance with the present invention.

FIG. 2 shows a partial cross sectional view of the brake drum of FIG. 1.

FIG. 3 shows a perspective view of the brake drum of FIGS. 1 and 2,wherein an air scoop has been installed at one of the air vents.

FIG. 4 shows a partial side view of the brake drum of FIG. 3, with theair scoop installed in accordance with the present invention.

FIG. 5 shows a perspective view of the air scoop shown in FIGS. 3 and 4,in accordance with the present invention.

FIG. 6 shows a partial side view of a brake drum, for use at the frontof a vehicle, having the air scoop of FIG. 5 installed in accordancewith the present invention.

FIG. 7 shows a second embodiment of the present invention, wherein anair scoop is installed on a brake drum for use at the front of avehicle.

FIG. 8 is a perspective view of the air scoop shown in FIG. 7, inaccordance with the present invention.

FIG. 9 is a third embodiment of the present invention and it shows apartial view of a mounting flange portion of a brake drum for use at thefront of a vehicle, in accordance with the present invention.

FIG. 10 shows a perspective view of the air scoop of FIG. 9, inaccordance with the present invention.

FIG. 11 is a fourth embodiment of the present invention and shows apartial perspective view of a mounting flange of a brake drum for use atthe front of a vehicle, in accordance with the present invention.

FIG. 12 shows a partial side view of the mounting flange of FIG. 11,having the air scoop in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 discloses a two-piece composite brake drum 10. The brake drumshown in FIG. 1 is designed for installation at the rear of a vehicle.Although FIG. 1 shows a rear two-piece composite brake drum, it willbecome apparent, from the further description, that the presentinvention is not limited to a two-piece composite drum, nor a rear drum.In fact, the present invention relates to brake drums in general. Theparticular brake drum shown in FIG. 1 includes a cylindrical main bodyportion or a steel shell portion 12 having a ribbed portion 14 and asquealer band 16. A mounting flange portion 18 is also shown andincludes a plurality of lug bolt openings 20 and a pilot hole 22. Themounting flange portion also includes a transition portion 24 having aplurality of notches 26. The mounting flange portion attaches to thecylindrical main body portion with a transition portion whereupon thenotches form a plurality of vent openings 28.

FIG. 2 shows a partial cross sectional view of the brake drum of FIG. 1.FIG. 2 more readily shows the ribbed portions, and the squealer band. Abrake liner portion or friction surface 30 is also shown. The mountingflange portion and steel shell portion form a brake drum cavity 32.

FIG. 3 is a perspective view of the brake drum shown in FIGS. 1 and 2.An air scoop 34 is shown mounted at one of the vent openings inaccordance with the present invention. Final assembly of the two-piececomposite brake drum in accordance with the present invention wouldnormally include an air scoop at each of the vent openings.

FIG. 4 is a partial side view of the brake drum of FIG. 3. The side viewof the air scoop 34 is shown at the top left of the figure.

FIG. 5 is a perspective view of the air scoop 34 shown in FIGS. 3 and 4.The air scoop includes a generally flat side wall 36 having a bottomedge 38, side edges 40 and an upper edge 42. The upper edge defines acurved or concave profile. A curved or concave back wall 44 extends froma first longitudinal side 46 at a substantially right angle from theupper edge. A curved or webbed side wall 48 extends from a secondlongitudinal edge 50 of the back wall at a generally inclined angle andin a radial direction and towards the outboard side of the air scoop.The webbed side wall includes a narrow portion 52 which extendslaterally in opposite directions in a diverging manner so as to formopposing wide end portions 54. The narrow portion extends furtherradially inward than does the opposing wide end portions. The webbedside wall defines an inboard curved edge 56 and an outboard curved edge58. A main body portion 60 extends towards the outboard side from theoutboard curved edge of the webbed side wall. The main body portiongenerally conforms with the transition portion of the mounting flangeportion. The air scoop of FIG. 5 may be installed on a brake drum suchas in FIGS. 3 and 4 via welding or similar mode of attachment such asknown in the art. It will be also appreciated that the air scoop of FIG.5 and as shown installed in FIGS. 3 and 4 is designed to operate on abrake drum regardless of whether the brake drum is mounted to the leftside or the right side of a vehicle. In particular, the air scoop ofFIG. 5 defines opposing louver openings 62 separated by a deflectorsurface 64 which is defined by a mid-portion 66 of the lower surface 68of the curved or concave back wall.

FIG. 6 is a partial side view of a brake drum which is adapted forinstallation at the front of a vehicle. The brake drum of FIG. 6includes the air scoop 34 of FIG. 5.

FIG. 7 relates to a second embodiment of the present invention. Apartial view of a brake drum is shown and which is adapted forinstallation at the front of a vehicle. The brake drum includes thecylindrical portion and the mounting flange portion having thetransition portion. The transition portion includes a plurality of ventopenings (not shown in FIG. 7) such as disclosed in the previousfigures. FIG. 7 differs from that of FIG. 6 as to the embodiment of theair scoop 70 to which is shown secured to the transition portion and thecylindrical portion, such as via welding or other similar attachmentmeans known in the art.

FIG. 8 shows a perspective view of the air scoop 70 of FIG. 7. The airscoop of FIG. 8 includes a flat inboard side wall 72 having an uppercurved or convex edge 74, a lower edge 76 and two substantially flatside edges 78. A curved or convex back wall 80 is shown to include aninboard longitudinal edge 82 from which the back wall extends at a rightangle from the inboard side wall. The back wall includes an outboardcurved edge 84 from which an angled side wall 86 extends radially andtowards the outboard side. The angled outboard side wall includes sideedges 88 and a distal edge 90. A planar mounting flange 92 extends fromthe distal edge and generally conforms to the transition portion of themounting flange. A deflective surface or webbed wall 94 extendsgenerally from the flat inboard side wall, along the underside of theback wall, and to the underside of the side wall. It will be appreciatedthat the deflector surface or webbed wall may be substantially planar ormay also be designed wherein the webbed wall extends radially outwardand in a diverging manner forming a curved deflector surface on opposingsides of the louver openings 96. The air scoop of FIG. 8 maybe secure tothe two-piece composite brake drum of FIG. 7 such as via welding orsimilar attachment means.

FIG. 9 discloses a third embodiment of the present invention. Inparticular, a partial view of the mounting flange portion of a brakedrum is shown. The mounting flange portion is adapted for installationat the front of a vehicle. The mounting flange portion includes thetransition portion having a plurality of vent openings (not shown) in amanner similar to that shown in the previous figures. An air scoop 100is shown secured to the transition portion over a vent opening inaccordance to the present invention.

The air scoop 100 of FIG. 9 is shown in the perspective view in FIG. 10.The air scoop includes a generally planar main body portion 102 having acurved portion 104. The planar main body portion and curved portiongenerally conform to the transition portion of the mounting flangeportion as shown in FIG. 9. The main body portion includes two sideedges 106 and an outboard edge 108. An opening 110 extends through themain body portion. A clip 112 extends from each of the side edges. Eachclip includes a main flange portion 114 extending radially inward, and alip portion 116. A louver 118 is located over the opening 110 anddefines a louver opening 120. The louver includes an inboard wall 122which is substantially at a right angle to the main body portion 102, anupper wall 124 which is substantially parallel to the main body portion102, an outboard wall 126 which is inclined at approximately a 45° angleto the main body portion 102. The walls 122, 124, 126 taper downwardlyaway from the louver opening 120 to a back side 128 of the louver at themain body portion. The air scoop of FIG. 10 maybe installed in a brakedrum via a snap fitted installation technique, wherein the clips extendthrough the vent opening into the brake drum cavity and the lip portionretains the scoop in position. Further, it will be appreciated that ifthe curved portion of the planar main body is omitted, the air scoop ofFIG. 10 could be installed on a brake drum regardless of which side ofthe vehicle the brake drum is to be installed.

FIG. 11 discloses a fourth embodiment of the present invention. Inparticular, FIG. 11 discloses a partial perspective view of a mountingflange of a brake drum. A mounting flange includes the transitionportion having a plurality of vent openings (of which only one isshown). An air scoop 130 is shown at the vent opening.

FIG. 12 is a partial side view of the mounting flange of FIG. 11. Theair scoop 130 is shown to include a back wall 132 extending from aninboard portion of the transition portion toward the outboard side. Theair scoop is further shown to include a side wall 134 extending from theback wall and radially outwardly toward the outboard side toward thetransition portion. The air scoop forms dual opposing louver openings136. The air scoop of FIGS. 11 and 12 maybe formed during a stamping andcutting process as an integral unit, or maybe a separate component whichis individually secured to the mounting flange such as via welding.

It will be appreciated that a brake drum having a plurality of airscoops in accordance with the present invention maybe installed on thevehicle. The air scoops will be typically secured to the transitionportion and/or cylindrical main body portion, and may be located withinthe air gap defined between the brake drum and wheel. Rotation of thewheel and brake drum combination will induce air flow into louveropening and into the brake drum cavity providing ventilation.Ventilation will aid in cooling, cleaning and the removing of debris. Itwill be further appreciated that the air scoops will have a tendency toprevent water from entering the brake drum such as during washing of thevehicle and wheels.

The present invention is applicable to a steel shell brake drum, atwo-piece brake drum, a composite brake drum, a cast brake drum, andother embodiments, as will be appreciated.

1. A brake drum comprising: a cylindrical main body portion whichdefines a brake drum cavity; a brake drum mounting flange portion; abrake drum transition portion, the brake drum transition portionextending between the cylindrical main body portion and the mountingflange portion, the transition portion having at least one vent opening;and an air scoop secured to the brake drum at the vent opening, wherebyrotation of the brake drum and air scoop induces air movement into thebrake drum cavity.
 2. The brake drum of claim 1, wherein the brake drumincludes a plurality of vent openings, and an air scoop secured at eachvent opening.
 3. The brake drum of claim 1, wherein the brake drum is afull cast iron brake drum.
 4. The brake drum of claim 1, wherein thebrake drum is a steel shell brake drum.
 5. The brake drum of claim 1,wherein the brake drum is a two-piece steel shell brake drum.
 6. Thebrake drum of claim 1, wherein the brake drum is a composite brake drum.7. The brake drum of claim 1, wherein the air scoop includes a louverhaving dual opposing openings, and a deflector surface located betweenthe dual opposing openings, the air scoop is secured at the vent openingwith the dual opposing openings each facing a respective direction ofrotation of the brake drum, with one of the dual opposing openings andthe deflecting surface, directing air flow into the brake drum, wherebythe air scoop will function properly regardless of whether the brakedrum is located on the left side or right side of a vehicle.
 8. Thebrake drum of claim 1, wherein the air scoop includes a substantiallyflat side wall having a bottom edge, top edge and opposing and parallelside edges, the flat side wall is in engagement with the brake drummounting flange portion, the bottom edge having a curved profile whichsubstantially conforms to the transition portion, the top edge having acurved profile, a concave or curved back wall extends substantially at aright angle from the curved top edge and toward the inboard side of thebrake drum, a curved or web side wall, opposite the flat side wall,extends from the curved back wall radially inwardly toward an exteriorsurface of the cylindrical main body portion, and a main body portionextends from the webbed angular side wall and conforms to the exteriorsurface of the cylindrical main body portion, whereby the concave backwall deflects air movement radially inward toward the brake drum cavity.9. The brake drum of claim 8, wherein the air scoop is welded to thebrake drum.
 10. The brake drum of claim 1, wherein the air scoopincludes a substantially flat side wall having a bottom edge, top edgeand opposing and parallel side edges, the flat side wall is inengagement with the brake drum mounting flange portion, the bottom edgehaving a curved profile which substantially conforms to the transitionportion, the top edge having a convex or curved profile, a convex orcurved back wall extends substantially at a right angle from the curvedtop edge and toward the inboard side of the brake drum, an angled sidewall, opposite the flat side wall, extends from the curved back wallradially inwardly toward an exterior surface of the cylindrical mainbody portion, and a mounting flange extends from the angled side walland conforms to the exterior surface of the cylindrical main bodyportion, and a webbed wall or deflective surface extends from the flatside wall to the angled side wall, whereby the deflective surfacedeflects air movement radially inward toward the brake drum cavity. 11.The brake drum of claim 10, wherein the air scoop is welded to the brakedrum.
 12. The brake drum of claim 1, wherein the air scoop includes asubstantially planar main body portion which substantially conforms toan outer surface of the cylindrical main body portion, the planar mainbody portion having an opening which corresponds generally to thedimensions of the vent opening, a upwardly curved portion extends fromthe planar main body portion, the upwardly curved portion substantiallyconforms to the brake drum transition portion, a first flange extendsfrom one side of the planar main body portion, and second flange extendsfrom another side of the planar main body portion, both of the first andsecond flanges include an inwardly radially extending main flangeportion and a lip portion extending from the main flange portion, alouver portion surrounding the planar main body portion opening andforming a louver opening, the louver having a first side wall, a secondside wall, and a back wall, the first side wall is on the inboard sideof the air scoop and extends radially outwardly at a substantially rightangle to the planar main body portion to a first height as measured fromthe longitudinal axis of the brake drum, the second wall is on theoutboard side of the air scoop and extends radially outwardly toward thefirst side wall to a second height as measured from the longitudinalaxis of the brake drum, the second height being less than the firstheight, the back wall extends between the first and second wall to formthe louver opening, the first and second wall and the back wall extendtoward the side of the air scoop opposite from the louver opening andblend into the planar main body portion.
 13. The brake drum of claim 12,wherein the air scoop is snap fitted into the vent opening of thetransition portion.
 14. The brake drum of claim 1, wherein the air scoopincludes a first wall which extends from the transition portion in adirection substantially towards the outboard side of the brake drum andover a portion of the vent opening, and a second wall which extends fromthe exterior surface of the cylindrical main body portion towards theinboard side of the brake drum and towards and connects to the firstwall and covers another portion of the vent opening, the first andsecond wall form a louver having a louver opening on opposing sides ofthe louver.
 15. The brake drum of claim 14, wherein the air scoop is anintegral part of the brake drum.
 16. A brake drum comprising: acylindrical main body portion which defines a brake drum cavity; a brakedrum mounting flange portion; a brake drum transition portion, the brakedrum transition portion extending between the cylindrical main bodyportion and the mounting flange portion, the transition portion havingan outer surface and at least one vent opening; and an air scoop securedto the brake drum at the vent opening, the air scoop includes a louveropening and extends outwardly from the outer surface of the brake drumtransition portion, whereby rotation of the brake drum and air scoopinduces air movement into the brake drum cavity.
 17. The brake drum ofclaim 16, wherein the air scoop includes a deflection surface located inan air channel of the air scoop and adjacent the vent opening.
 18. Thebrake drum of claim 17, wherein the air scoop includes a louver openingon both sides of the deflection surface, and brake drum may be mountedto either the left or right side of the vehicle and the air scoop willdirect air into the vent opening via one of the louver openings.
 19. Thebrake drum of claim 16, wherein each air scoop is a discrete item whichis individually secured to the brake drum.
 20. A brake drum comprising:a cylindrical main body portion defining a brake drum cavity; a brakedrum mounting flange portion; a brake drum transition portion, the brakedrum transition portion extending between the cylindrical main bodyportion and the mounting flange portion, the transition portion havingan outer surface and a plurality of vent openings; and an air scoopsecured to the brake drum at each vent opening and which extendsoutwardly from the outer surface of the braked drum transition portion,each air scoop defines a louver opening which faces the anticipatedangular direction of drum rotation, an air channel in fluidcommunication with the louver opening and the brake drum cavity, and adeflection surface located in the air channel, the deflection surfacepositioned to re-direct air movement entering the louver opening at anangular direction, to a generally radial and inboard direction, wherebyrotation of the brake drum and air scoop induces air movement into thebrake drum cavity.